Image sensors have become ubiquitous. They are widely used in digital still cameras, cellular phones, security cameras, medical devices, automobiles, and other applications. The technology used to manufacture image sensors, and in particular complementary metal-oxide semiconductor (“CMOS”) image sensor (“CIS”), has continued to advance at a great pace. Modern image sensor applications place demands for faster processing speeds and better image quality, while simultaneously expecting miniaturization in the physical size of the image sensor. So new architectures need to be developed to improve the performance while maintaining or reducing the size of the image sensor circuits to keep pace with these demands.